Circuit Description - DTC P3120 - Information Codes 234, 235, 236, 237: Notes

WARNING: This page is about a different car, the 2002 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

When using an OBD II scan tool other than TOYOTA hand-held tester, check all the steps.
When using TOYOTA hand-held tester, confirm the information code and check it.

The HV ECU checks the energy balance and detects abnormality if the magnetism of the motor or generator greatly decreases.